<!DOCTYPE html>
<html lang="en">
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    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    
</body>
<script>
        let aa=prompt("请输入年份", "");
            if (aa%4==0&&aa%100!=0||aa%100==0&&aa%400==0){
                console.log(true);
            } else {
                console.log(false);
            }
        let cc=prompt("请输入年龄", "");
        if (cc > 17){
            console.log("成年了");
        } else{
            console.log("未成年");
        }

</script>
</html>